Spark falling to negative and amost dieing at idle
10-01-2011, 02:33 PM
#1
Spark falling to negative and amost dieing at idle I've been having an issue with my truck almost wanting to die every time I stop. I though it was to low on required air flow and was messing with it, but I'd get it to where it was better, then it would "cruise control" all the time driving it around cuz air flow was set too high.
So today I did some logging and I found out it is dropping the spark down very low every time it would come to an idle especial in gear. RPM would drop to 2-300 then spark would jump back up to 14-20 and dance like it's supposed to at idle. I noticed that every time it would do it's near dieing/dieing thing, it would be cuz the spark is like 0 to -5 or really low, then it would bounce back up and all is fine. I logged all the spark pids and can't find anything pulling timing and all the base spark number are set around 25* so I'm stumped...
Any one have any idea what's dropping my timing so much??? Seems the worst when it goes from rolling idle to complete stop. Here is my current tune and log to show what its doing...
So today I did some logging and I found out it is dropping the spark down very low every time it would come to an idle especial in gear. RPM would drop to 2-300 then spark would jump back up to 14-20 and dance like it's supposed to at idle. I noticed that every time it would do it's near dieing/dieing thing, it would be cuz the spark is like 0 to -5 or really low, then it would bounce back up and all is fine. I logged all the spark pids and can't find anything pulling timing and all the base spark number are set around 25* so I'm stumped...
Any one have any idea what's dropping my timing so much??? Seems the worst when it goes from rolling idle to complete stop. Here is my current tune and log to show what its doing...
Last edited by kbracing96; 10-01-2011 at 02:52 PM.
10-01-2011, 05:45 PM
#2
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Can't tell when you stopped because you didn't log VSS... would also be helpful if you logged airflow (grams/cyl) so it is possible to see where you are on the timing tables... speaking of which, what the hell did you do with your high octane timing table - it is a mess...
10-01-2011, 06:48 PM
#3
Can't tell when you stopped because you didn't log VSS... would also be helpful if you logged airflow (grams/cyl) so it is possible to see where you are on the timing tables... speaking of which, what the hell did you do with your high octane timing table - it is a mess...
The spark table is just a simple one I've been playing with for boost.
10-01-2011, 07:01 PM
#4
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Well, if you are not moving, when you let off the throttle, you are in the base spark in gear table... but, you still need to log airflow so you can see where you are in the tables - there are negative values in the table. You need to figure out if the timing is a cause or an effect... what is the AFR when this is happening?
10-01-2011, 07:22 PM
#6
This all started after I did the cam swap, went from a Vinci ultra torque to an Iski 212/212 .561/.561 112 +2 lsa.
I have a tune a guy on EFIlives forum just fixed up for me, I'll try it and see what happens.
I have been behind in my software version cuz what I had was working and didn't feel like messing with it but had to up date to open the tune he sent me, maybe that is part of the problem...
I have a tune a guy on EFIlives forum just fixed up for me, I'll try it and see what happens.
I have been behind in my software version cuz what I had was working and didn't feel like messing with it but had to up date to open the tune he sent me, maybe that is part of the problem...
10-01-2011, 09:02 PM
#7
Man I don't know what they did, but after the latest update I just did for the software I don't have half the pids I used to have... I can't even find GM.AFR to log... Can't find the pid to log calculated air flow since I don't have a MAF and run 2bar SD... Some thing is weird here...
I leaned it out and tried the other tune I got but it still wants to die and surge all the time at idle... Timing still drops way down right as the RPM falls... This has me stumped...
I leaned it out and tried the other tune I got but it still wants to die and surge all the time at idle... Timing still drops way down right as the RPM falls... This has me stumped...
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10-02-2011, 05:14 PM
#9
I did figure out the issue of the missing PIDs, its an issue with usung the auto update in the efilive software. I down loaded the current vertion from there web site and installed it over top and all the PIDs are back now. Haven't had a chance to try the other tune I got yet.
10-03-2011, 08:49 PM
#10
I only have 25% E85 and 93oct in the tank for the track. When I tune for that, I just bump the VE's 6% and if falls right in line so when I burn that tank out, I can just go back to my other VE tables. It is 2 bars COS3 tuned. The VE tables are tuned in with auto VE. The injectors are siemen deka 60's on 58PSI which makes them about 70's
I did figure out the issue of the missing PIDs, its an issue with usung the auto update in the efilive software. I down loaded the current vertion from there web site and installed it over top and all the PIDs are back now. Haven't had a chance to try the other tune I got yet.
I did figure out the issue of the missing PIDs, its an issue with usung the auto update in the efilive software. I down loaded the current vertion from there web site and installed it over top and all the PIDs are back now. Haven't had a chance to try the other tune I got yet.
about 15% differt than 6000@105kpa idle would be pretty fat. Widebands are notoriuos liars about lean at idle. Sometimes tuning it like a carb works well
go for the best vaacum reading.
